1. Field of Invention
This invention relates to lawn/turf mowing machines, and more particularly to an implement governing mechanism and method for such machines.
2. Description of Related Art
Lawn/turf mowing machines are well-known. Such machines commonly have a separably operable engine and cutting deck mounted on a chassis. A gear shift lever, positioned in either forward gear or a reverse gear by the operator, controls the direction of travel of the mowing machine.
Industry has recognized the safety concerns posed by mowing machines having cutting blades engaged when the mowing machines travel in a reverse direction. For example, U.S. Pat. No. 3,984,867 provides a mechanical interlock preventing cutting in reverse. U.S. Pat. No. 3,999,643 discloses a mower having a transmission lever that, in the reverse position, opens a switch to disengage an electric clutch operatively associated with the cutting blade. Newly proposed 2003/2004 ANSI Safety Standard requires a No Mow In Reverse (NMIR) feature on mowing machines. U.S. Pat. No. 6,026,634 also discloses disengagement of the cutting blades when a zero turn radius (ZTR) mowing machine is in full reverse gear.
Current technology for precluding the engagement of cutting blades for self-propelled and ride-on machines includes:    a. A mechanical means that blocks reverse drive of the mowing machine when cutting blades are engaged.    b. An electronic means that blocks reverse drive of the mowing machine when cutting blades are engaged.    c. An electronic means that automatically disconnects power to the cutting blades when the mowing machine's directional control is changed into Reverse. These systems are usually equipped with a “latching relay” that requires the system to be reset to re-engage the cutting blades in machine “Neutral” or “Forward” travel directions.    d. A mechanical means that disconnects power to the cutting blades when the mowing machine's directional control is changed to Reverse and requires the system to be reset to re-engage the cutting blades when the machine direction control is returned to Neutral or Forward travel directions.
In a and b above, shifting into reverse is prevented, whereas in c and d above, use of the cutting blades is prevented until the system is reset. In order to satisfy the above safety concerns about cutting in reverse while still allowing for optimal operator convenience, it is desirable to provide a lawn/turf mowing machine in which the cutting blades are automatically disengaged in reverse and then automatically re-engaged solely by shifting the mowing machine into an appropriate gear position.